As an electric connection box for controlling conduction/shutoff of in-vehicle electrical components mounted on a vehicle, like the one described in Patent Document 1 has been known. This electric connection box is manufactured by loading a circuit component with its body faced vertically in a case in the shallow disk state, blocking an opening of the case with a cover and filling a filler material through a passage hole formed in the cover so that the circuit component is buried (See FIG. 8 of Patent Document 1). Heat generated from the circuit component is transmitted to the case and a wall surface of the cover via the filler material and radiated to the outside the electric connection box.
[Patent Document 1]
Japanese Patent Laid-Open No. 2003-31979